/Engine/Plugins/Enterprise/DatasmithImporter/Source/DatasmithImporter/Public/ObjectElements/DatasmithUObjectElements.h
Set the material name to associate with slot SlotId
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(BlueprintCallable, Category="Datasmith | Element") void SetMaterial ( const [FString](API\Runtime\Core\Containers\FString) & MaterialName, int32 SlotId )